The present invention relates generally to thermally-actuated cartridges for fire dampers for airflow ducts, but also relates more generally to any thermally-actuated mechanism and any damper for airflow ducts.
WO 02/43810 and EP0 300992 disclose the use of thermal cartridges for closing the damper element of a fire damper in an airflow duct. There can be problems with the cartridge if it is wrongly installed. For instance, if it is screwed in too tightly, the solder (or other heat-softenable or meltable material) can rupture, but there is no indication that this has occurred so that if there is a fire, the damper element does not close.
The installation of a member for carrying the cartridge and arranging for the retention of the damper element can give significant difficulty.